1. Field of the Invention
The invention relates to graphene dendrites with multiple branches of considerable aspect ratios and a method for growing such graphene structures on a solid surface, of which neighboring graphene branches may merge to form graphene plates.
2. Description of Related Art
Graphene refers to a two-dimensional material having a beehive-like lattice arrangement formed by carbon hybrid orbitals. It is optically transparent and has extraordinarily high thermal conductivity and electron mobility at room temperature as well as atomic level of low thickness and high mechanical strength. The unique and exceptional properties of graphene have lent itself to extensive industrial applicability in the functioning of photonic and electronic parts, fuel cells, electrochemical products, sensory devices, field emission, hydrogen storage and other power-supplying materials.
The currently known methods of making graphene include, for example, the following: (1) in separation method, individual graphene plates are separated from a graphite crystal by mechanical means or chemical means and their combination; however the size of the graphene plates synthesized from this method generally tend to be smaller than the graphite crystal so are not suitable for use in large-area applications; (2) in another method, silicon carbide are heated to a high temperature to remove silicon, which results in single-layer or multilayer graphene; but the graphene of such type cannot be easily adapted for uses on non-silicon carbide substances; and it can face problems when it is needed to prepare large-area graphene of a uniform thickness; (3) chemical vapor deposition is currently the most popularly known preparation method for making graphene; but its inclination to produce monolayer and multilayer polycrystalline graphene having island-like, small crystalline domains and plural grain boundaries can make it difficult to achieve flat monolayer, graphene having large crystalline domains, or large-area monolayer graphene plates. Besides, graphene formed by conventional chemical vapor deposition methods exhibits the morphology of a continuous film or plate. In consideration of the above issues, the present invention aims to provide graphene dendrites with high aspect ratios in their branches and a method for making the same including the formation of large, snowflake-like continuous single-crystalline monolayer graphene dendrites by starting with chemical vapor deposition method under a low gas pressure to prepare single crystalline, monolayer graphene nuclei; growing the graphene nuclei into a novel configuration, where the configuration refers to single-crystalline, monolayer graphene dendrites including snowflake-like graphene having branches of large aspect ratios, and, through modulating carbon etching gas, for example, hydrogen, and carbon source gases, for example, methane, supply, and combining the branches of one or more graphene dendrites to form a continuous graphene plate, including for example, single-crystalline and monolayer graphene plates